Priority charging system

ABSTRACT

Previously charged surge tanks supply the initial charging gas for delivery tanks until a predetermined pressure between gas in the delivery tanks and the surge tanks is reached, at which point a compressor charges the delivery tanks. The surge tanks are themselves charged when the pressure in an outlet line from the compressor reaches a predetermined value.

e llmted States Patent 1151 3,653,394 dunes [4 1 Apr. 4, I972 [54] PRIORITY CHARGING SYSTEM 3,031,105 4/1962 Walker ..137/119 x 3,504,686 4/1970 Cooper et al. ..l37/568 X [72] Inventor: Robert W. McJones, 529 Via Del Monte,

Palos Verdes Estates, Calif. 90274 Primary Examiner-Herbert F. Ross Assistant Examiner-David J. Zobkiw [22] 1970 Attorney-Christie, Parker & Hale [21] Appl. No.: 86,843

[57] ABSTRACT 52 us. 01 ..137/114, 137/119, 137/568 previPsly charged sufge tanks SUPPIY Charging gas V for delivery tanks untll a predetermined pressure between gas [51] Int. Cl. ..G05d 11/00 1n the delrvery tanks and the surge tanks is reached, at which [58] Field of Search ..l37/l 11, 114, 1 l5, 117, 118, point a compressor charges the delivery tanks The surge 137/119, 568; 138/226 tanks are themselves charged when the pressure in an outlet line from the compressor reaches a predetermined value. [56] References Cited 3 Claims, 1 Drawing Figure UNITED STATES PATENTS 764,269 7/1904 Broderick ..l38/26 X mn/fleaw/e e I Z0 \Z2 F I F I 40 8 7 I is I i j) w. e Z .94 50%; m/vx 30 26 J 2; 35

Patented April 4, 1972 wmbwwwwwsm BACKGROUND-OF THE INVENTION The present invention relates in general to compressor systems and, more in particular, to a compressor system especially adapted to effect the rapid charging of delivery tanks.

It has been recently recognized that the use of natural gas as a fuel for internal combustion engines, typically in motor vehicles, can greatly reduce the amount of pollutants of carbon monoxide, oxides of nitrogen and hydrocarbons in the exhaust from such engines. One way of storing natural gas in a vehicle is in its gaseous state in tanks. Typically these tanks are rated at a relatively high pressure, say, 2,265 p.s.i. at standard temperature.

Quite obviously, a vehicles tanks must be charged from time to time and it is highly desirable to effect charging in the shortest period of time. Presently available compressor systems are not capable in and of themselves of providing relatively rapid charging of a vehicles gaseous fuel tanks because of the capacity of the tanks and the compressor.

As a consequence, there is a need for a compressor system which will effect the rapid charging of tanks or the like.

SUMMARY OF THE INVENTION surge tanks.

In greater detail, the present invention contemplates one or more surge tanks coupled to the outlet side of a compressor and means to couple the outlet of the compressor to the delivery tanks to be charged. The surge tank is charged when the outlet pressure from the compressor reaches a predetermined value of, say, 2,400 p.s.i. The surge tank itself charges the delivery tanks when the pressure in the surge tank is higher than that in the delivery tank.

A specific form of the present invention contemplates a compressor adapted to be coupled to a source of gas and having an outlet. A selectively actuatable delivery valve is coupled in fluid circuit with the outlet of the compressor to couple the outlet of the compressor to the delivery tanks. The surge tank is coupled in fluid circuit to the outlet of the compressor between the delivery valve and the outlet. A backpressure valve between the outlet of the compressor and the surge tank admits to surge tank charging when the pressure at the outlet reaches a predetermined value of, say, 2,400 p.s.i. A check valve prevents flow to the surge tank at pressures below the predetermined value.

When the surge tank is charged and the delivery valve is opened, the surge tank will charge the delivery tanks. When pressure equilibrium exists between the surge tank and the delivery tanks, the compressor charges the delivery tanks. When the pressure at the outlet of the compressor reaches the predetermined value, as when the delivery valve is closed and the compressor is operating, the surge tank will be charged.

Thus, the present invention provides a compressor system which effects very rapid charging of delivery tanks for a given capacity compressor.

These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawing.

BRIEF DESCRIPTION OF THE FIGURE The single FIGURE is a flow sheet of the improved priority charging system of the present invention.

2 DESCRIPTION OF THE PREFERRED EMBODIMENT A compressor 10 has an inlet 12 and an outlet 14. Inlet 12 is coupled in fluid circuit through a line 16 to a source of gas 18. An inlet valve 20 controls the flow of gas from the source of gas to the compressor.

Outlet 14 is coupled in fluid circuit to a line 22 for charging delivery tanks. A delivery valve 24 in line 22 provides for the selective communication between the outlet of the compressor and the delivery tanks.

A bank of surge tanks 26, which tanks, is in fluid circuit with line through a line 28 and a branch line 30. Valves 32 from each of the surge tanks to line 28 provide the means for installation and removal of the surge tanks from the system illustrated. In any event, valves 32 are each in series fluid circuit with line 28 through parallel branches 34.

Line 30 has a backpressure valve'36 between it and its junctions with lines 22 and 28. This backpressure valve permits flow of gas from line 22 into line 28 only when a predetermined pressure is reached, for example, 2,400 p.s.i.g. A check valve 38 in line 28 is disposed in parallel fluid circuit with backpressure valve 36 to permit gas flow from surge tanks 26 to line 22 only when the pressure in the surge tanks exceeds the pressure in line 22 by a predetermined amount.

A relief branch 40 couples the outlet of compressor 10 to its inlet through a relief valve 42. This valve is set to communicate the inlet and outlet of the compressor at a predetermined pressure of, say, 2,700 p.s.i.

In use, delivery tanks are coupled in line 22 and valve 24 is opened. In the event that the surge tanks 26 have gas under a pressure higher than present in the delivery tanks, the surge tanks will charge the delivery tanks through line 28 and check valve 38 until a predetermined pressure differential exists between them, typically when pressure equilibrium exists between them. At this point, compressor 10 through line 22 will charge the delivery tanks. Compressor 10 may be operated even while the surge tanks are blowing down. Eventually the delivery tanks will reach a pressure corresponding to the opening pressure of backpressure valve 36, or, valve 24 is closed enabling the pressure in line 22 to increase to the triggering pressure for valve 36. In either event, when that pressure is reached, valve 36 will open line 22 to line 28 to bypass check valve 38 and effect the charging of the surge tanks.

Thus the present invention provides a compressor system which effects the priority charging of delivery tanks by initially using the pressure in surge tanks to effect the charging and then, if necessary, coupling the delivery tanks to the compressor directly. In the event that the surge tanks are at a pressure lower than the delivery tanks initially, however, the delivery tanks in the priority system described will be directly coupled to the compressor.

The present invention has been described with reference to a certain preferred embodiment. The spirit and scope of the appended claims should not, however, necessarily be limited to the foregoing description.

What is claimed is:

1. A priority charging system for charging tanks and the like to a predetemiined delivery pressure comprising:

a. a compressor having an inlet for receiving low pressure gas from a source thereof and an outlet for discharging compressed gas;

b. means for selectively communicating the outlet with a delivery point;

c. at least one surge tank in fluid circuit with the outlet between the selective communication means and the outlet;

d. means for communicating the outlet and the surge tank for gas flow from the outlet to the surge tank only when a predetermined pressure exists at the outlet which is at least as much as the predetermined delivery pressure;

e. means for communicating the surge tank with the delivery point only when surge tank pressure exceeds delivery point pressure; and

may be one or more surge 22 for the receipt of gas f. means for preventing gas flow from the delivery point to 3. The priority charging system claimed in claim 2 wherein:

h Surge f relief means is provided between the outlet and the inlet 2. The priority charging system claimed 1n claim 1 wherein: operable to communicate the two when outlet pressure the means for communicating the outlet and the surge tank includes a backpressure valve between them operable to 5 admit gas flow from the outlet to the surge tank at the predetermined outlet pressure.

exceeds the predetermined delivery pressure by a predetermined amount. 

1. A priority charging system for charging tanks and the like to a predetermined delivery pressure comprising: a. a compressor having an inlet for receiving low pressure gas from a source thereof and an outlet for discharging compressed gas; b. means for selectively communicating the outlet with a delivery point; c. at least one surge tank in fluid circuit with the outlet between the selective communication means and the outlet; d. means for communicating the outlet and the surge tank for gas flow from the outlet to the surge tank only when a predetermined pressure exists at the outlet which is at least as much as the predetermined delivery pressure; e. means for communicating the surge tank with the delivery point only when surge tank pressure exceeds delivery point pressure; and f. means for preventing gas flow from the delivery point to the surge tank.
 2. The priority charging system claimed in claim 1 wherein: the means for communicating the outlet and the surge tank includes a backpressure valve between them operable to admit gas flow from the outlet to the surge tank at the predetermined outlet pressure.
 3. The priority charging system claimed in claim 2 wherein: relief means is provided between the outlet and the inlet operable to communicate the two when outlet pressure exceeds the predetermined delivery pressure by a predetermined amount. 